What's really remarkable about this graph is the crazy number of variables it manages to keep track of while staying lucid. A total of six, including the size of Napoleon's army, the direction it was headed, the temperature on various days, and even off-shoot sorties from the whole doomed campaign.

Of course until you have some explanation it just looks like a weird line, and it doesn't help that the description is written in French. Fortunately the Numberphile walkthrough is more than detailed enough to help you learn a little about history; the history of infographics and the history of why not to invade Russia in the winter. [Numberphile]